Catalyst comprising a phyllosilicate containing boron and/or silicon, and a hydrocracking process

ABSTRACT

The invention concerns a catalyst comprising at least one matrix, at least one dioctahedral 2:1 phyllosilicate which is optionally synthesised in a fluorine-containing medium and optionally bridged, at least one metal selected from elements from group VIB and/or group VIII of the periodic table, boron and/or silicon, optionally phosphorous, optionally at least one group VIIA element, and optionally at least one group VIIB element. The invention also concerns the use of the catalyst for hydrocracking hydrocarbon-containing feeds.

[0001] The present invention relates to a catalyst comprising at leastone metal selected from metals from group VIB and/or VIII (group 6 andgroups 8, 9 and 10 in the new periodic table notation: Handbook ofChemistry and Physics, 76^(th) edition, 1995-1996, inside front cover),associated with a support comprising at least one porous amorphous orlow crystallinity oxide type matrix and at least one clay selected fromthe group formed by 2:1 octahedral phyllosilicates and trioctahedral 2:1phyllosilicates. The catalyst support comprises at least one promoterelement which is boron and/or silicon, optionally phosphorous,optionally at least one group VIIA element (group 17, the halogens), inparticular fluorine, and optionally at least one group VIIB element.

[0002] The present invention also relates to processes for preparingsaid catalyst, and to its use for hydrocracking hydrocarbon-containingfeeds such as petroleum cuts and cuts from coal. The feeds containaromatic and/or olefinic and/or naphthenic and/or paraffinic compounds,said feeds possibly containing metals and/or nitrogen and/or oxygenand/or sulphur.

[0003] Hydrocracking is gaining in importance in refining as the need toconvert heavy fractions into lighter fractions which can be upgraded asfuels increases. This results from the increasing demand for fuels. Suchupgrading involves a relatively large reduction in the molecular weightof the heavy constituents which can, for example, be achieved throughcracking reactions.

[0004] The catalytic hydrocracking process uses catalysts containing ahydrogenating, desulphurising and denitrogenating function provided bythe active phase based on transition metals, and an acidic function,generally provided by the amorphous matrix or a zeolite, or a mixturethereof. A good hydrocracking catalyst will be constituted by a properlyadjusted hydrogenating function and acidic function. Hydrocracking isused to treat feeds such as vacuum gas oils, atmospheric or vacuumresidues, which may or may not be deasphalted. Hydrocracking can producehighly purified lighter cuts, i.e., with a low sulphur, nitrogen andmetals content.

[0005] Increasing the activity and selectivity of hydrocrackingcatalysts is thus important. One means consists of acidifying the matrixwithout poisoning the activity of either the transition-metal basedhydrogenating phase or the cracking activity of the zeolite-based acidicphase.

[0006] The invention thus relates to a catalyst for hydrocrackinghydrocarbon-containing feeds. The catalyst contains at least one metalselected from group VIB and group VIII of the periodic table. Thecatalyst also comprises at least one clay selected from the group formedby dioctahedral 2:1 phyllosilicates and trioctahedral 2:1phyllosilicates such as kaolinite, antigorite, chrysotile,montmorillonite, beidellite, vermiculite, talc, hectorite, saponite, orlaponite. The catalyst preferably contains a dioctahedral 2:1phyllosilicate synthesised in a fluoride medium and optionally bridged,said phyllosilicate preferably having a large interplanar spacing. Thecatalyst also comprises at least one amorphous or low crystallinitymatrix acting as a binder. The catalyst is characterized in that it alsocomprises boron and/or silicon, optionally phosphorous, optionally atleast one group VIIA element, preferably fluorine, and optionally atleast one group VIIB element, for example manganese, technetium orrhenium.

[0007] The catalyst has a higher hydrocracking activity than that ofprior art catalytic formulae based on clay. Without wishing to be boundto a particular theory, it appears that this particularly high activityof the catalysts of the present invention is due to the acidity of thecatalyst being reinforced by the presence of boron and/or silicon, inparticular on the matrix, which causes an improvement in thehydrocracking properties compared with catalysts in routine use.

[0008] More precisely, the present invention provides a catalystcomprising at least one dioctahedral 2:1 phyllosilicate, which isoptionally bridged. When it is bridged, the interplanar spacing is atleast 2.0×10⁻⁹ m and comprises struts based on at least one compoundselected from the group formed by SiO₂, Al₂O₃, TiO₂, ZrO₂ and V₂O₃, orany combination thereof.

[0009] The interplanar spacing d₀₀₁ of the dioctahedral 2:1phyllosilicates of the invention (preferably previously prepared in afluoride medium in the presence of HF acid and/or another source offluoride ions) is preferably at least 2.0×10⁻⁹ m, more preferably atleast 2.65×10⁻⁹ m, more preferably more than 2.8×10⁻⁹ m and still morepreferably still at least 3.3×10⁻⁹ m, and generally 6.0×10⁻⁹ m or less,preferably 5.0×10⁻⁹ m. The interplanar spacing, represented by d₀₀₁,represents the sum of the thickness of a sheet and the space between thesheets. This value can be directly obtained using a conventionalorientated powder X ray diffraction method.

[0010] Dioctahedral 2:1 phyllosilicates are minerals which are formed bylayering elementary sheets. Although the chemical bonds between theelements of the phyllosilicate structure are ionocovalent, they will beassumed to be ionic, to simplify the description.

[0011] From a representation where the O²⁻ ions are in a plane incontact with each other, it is possible to produce a plane with ahexagonal cavity, termed the hexagonal plane, by withdrawing alternateO²⁻ ions from a row of two O²⁻ ions.

[0012] The structure of a dioctahedral 2:1 phyllosilicate can be simplyrepresented by arrangements of hexagonal planes of O²⁻ ions and compactplanes of O²⁻ and OH ions. The OH ions fill the cavities in thehexagonal planes of O²⁻ ions.

[0013] Superimposition of two compact planes sandwiched by hexagonalplanes defines an octahedral layer (O) between two tetrahedral layers(T) giving the sheet denomination TOT.

[0014] Such an arrangement, also termed 2:1, defines a plane ofoctahedral cavities located in the octahedral layer between two planesof tetrahedral cavities, one in each tetrahedral layer. Each tetrahedronhas one O²⁻ ion in common with the octahedral layer and each of thethree other O²⁻ ions is shared with another tetrahedron in the sametetrahedral layer.

[0015] The crystalline lattice is thus constituted by 6 octahedralcavities each having 4 tetrahedral cavities either side. In the case ofa phyllite constituted by the elements Si, Al, O, H, such an arrangementcorresponds to the ideal formula Si_(g)(Al₄*₂)O₂₀(OH)₄. The tetrahedralcavities contain the element silicon, and the octahedral cavitiescontain the element aluminium but in this case one octahedral cavity inthree is empty (*). Such an assembly is electrically neutral. Usually,the half-cell is used, with formula

[0016] Si₄(Al₂*)O₁₀(OH)₂

[0017] The tetrahedral element silicon can be substituted by trivalentelements such as aluminium or gallium or iron (Fe³⁺). Similarly, theoctahedral element aluminium can be substituted by:

[0018] the trivalent elements cited above, or a mixture of thoseelements;

[0019] divalent elements, for example magnesium.

[0020] These substitutions result in an overall negative charge in thestructure. This necessitates the existence of exchangeable compensatingcations located in the space between the sheets. The thickness of thespace between the sheets depends on the nature of the compensatingcations and their hydration. This space is also capable of acceptingother chemical species such as water, amines, salts, alcohols, or bases.

[0021] The existence of —OH groups causes thermal instability due to adehydroxylation reaction with equation:

2−OH→-O-+H₂O.

[0022] In this respect, and without wishing to be bound to a particulartheory, it can be considered that the introduction of the elementfluorine into the structure during synthesis in place of the O—H groupsproduces phyllosilicates with greatly improved thermal stability.

[0023] The preferred phyllosilicates of the invention are dioctahedral2:1 phyllosilicates the characteristics of which are given below, intowhich struts have been introduced into the space between the sheets (thestruts being selected from S₂O₂, Al₂O₃, TiO₂, ZrO₂, V₂O₅), so as toproduce an interplanar spacing d₀₀₁ of at least 2.0×10⁻⁹ m.

[0024] The general chemical formula (for a half-cell) of dioctahedral2:1 phyllosilicates, preferably synthesised in a fluoride medium in thepresence of HF acid and/or another source of fluoride anions, beforebridging is as follows:

M^(m+)x/m((Si_((4-x))T_(x)) (T₂ ₁)O₁₀(OH_((2-y))F_(y))^(x−)

[0025] where

[0026] T represents an element selected from the group formed byelements from group IIIA (such as B, Al, Ga) and iron;

[0027] M is at least one compensating cation selected from the groupformed by cations of elements from groups IA, IIA and VIII, organiccations containing nitrogen, the ammonium cation, and rare earthcations. The cation originates from the reaction medium or is introducedby at least one exchange process. Advantageously, the cation from thereaction medium is selected from the group formed by alkalis (exceptlithium), the ammonium cation (NH₄ ³⁰ ), organic cations containingnitrogen (including alkylammonium and arylammonium) and organic cationscontaining phosphorous (including alkylphosphonium and arylphosphonium).M can also be a compensating cation introduced by post-synthesis ionexchange, selected from the group formed by cations of elements fromgroups IA, IIA and VIII of the periodic table, rare earth cations(cations of elements with atomic number 57 to 71 inclusive), organiccations containing nitrogen (including alkylammonium and arylamnmonium)and the ammonium cation;

[0028] m is the valency of cation M;

[0029] x is a number which is in the range 0 to 2, preferably in therange 0.1 to 0.8;

[0030] y is a number which is in the range 0 to 2; if the phyllosilicatecontains fluorine, Y is greater than 0:

[0031] and represents an octahedral cavity.

[0032] The X ray diffraction diagram of the dioctahedral 2:1phyllosilicate before bridging is characterised by the presence of thefollowing lines:

[0033] a characterising line, d₀₆₀, at 1.49±0.01×10⁻⁹ m for adioctahedral 2:1 phyllosilicate comprising an octahedral layer with thecomposition Si(Al₂);

[0034] at least one 001 reflection such that d₀₀₁ is 1.25±3×10⁻¹⁰ mdepending on the nature of the compensating cation and its hydration atthe humidity under consideration.

[0035] Preferably, the fluorine content is such that the F/Si molarratio is in the range 0.1 to 4, preferably 0.1 to 2.

[0036] The dioctahedral 2:1 phyllosilicate also exhibits at least onesignal in ¹⁹F NMR, with magic angle spinning, determined as is wellknown to the skilled person. The chemical displacement of this signalalso depends on the composition of the octahedral layer. Thus itcorresponds to a value of:

[0037] −133 ppm (±5 ppm) for ¹⁹F NMR, with magic angle spinning when thefirst neighbours of the F are two aluminium atoms, corresponding to anoctahedral layer with the composition Si(Al₂);

[0038] −108 ppm (±5 ppm) For ¹⁹F NMR, with magic angle spinning when thefirst neighbours of the F are two gallium atoms, corresponding to anoctahedral layer with the composition Si(Ga₂);

[0039] −118 ppm (±5 ppm) for ¹⁹F NMR, with magic angle spinning when thefirst neighbours of the F are an aluminium atom and a gallium atom,corresponding to an octahedral layer with the composition Si(Ga, Al).

[0040] The phyllosilicates are advantageously synthesised in a fluoridemedium in the presence of HF acid and/or another source of fluorideanions and at a pH of less than 9, preferably in the range 0.5 to 6.5.

[0041] The preparation of these types of solids in a fluoride medium andtheir characterisation are described in the following references, thedisclosures of which are hereby included in the present description:French patent FR-A-2 673 930, a publication of the 202^(nd) meeting ofthe American Chemical Society (ACS) in New York in August 1991,published in “Synthesis of Microporous Materials, Extended Clays andOther Microporous Solids” (1992), and a report of the “Academie desSciences Paris, t. 315, Series II, p. 545-549, 1992.

[0042] The dioctahedral 2:1 phyllosilicates described above canadvantageously contain fluorine and are bridged, for example using anovel process comprising the following steps:

[0043] The dioctahedral 2:1 phyllosilicate, preferably in its ammoniumform (NH₄ ⁺), is suspended in a solution of a surfactant with aconcentration in the range 0.01 mole/litre to 1 mole/litre, preferablyin the range 0.05 to 0.7 mole/litre, Suitable surfactants for use inthis step are anionic surfactants, non limiting examples of which arealkylsulphates and alkylsulphonates, or cationic surfactants, includingtetraalkylammonium halides or hydroxides such as cetyltrimethylammoniumchloride or geminal alkylammonium compounds. Examples arehexadecyltrimethylammonium bromide, ethylhexadecyldimethylammoniumbromide, octadecyltrimethylammonium bromide, dodecyltrimethylammoniumbromide, and didodecyldimethylammonium bromide. Other surfactants canalso be used, for example triton X-100, polyethylene oxide (POE).

[0044] After a contact period, during which the medium is stirred, forexample, taking 5 minutes to 12 hours, preferably 15 minutes to 6 hours,and more preferably 15 minutes to 3 hours, the medium is filtered thenwashed with distilled water and finally dried in air or an inert gas,for example at a temperature in the range 40° C. to 150° C.; for aperiod in the range 5 minutes to 24 hours, preferably in the range 30minutes to 12 hours. When the phyllosilicate is not in the ammoniumform, it can first undergo any treatment which is known to the skilledperson to obtain the dioctahedral 2:1 phyllosilicate mainly in itsammonium form. A non limiting example of a treatment to carry out thistransformation is an ion exchange step using aqueous solutions of anammonium salt (ammonium nitrate and/or ammonium chloride).

[0045] The dioctahedral 2:1 phyllosilicate treated using the operatingprocedure described in the preceding step is then brought into contactwith a mixture comprising:

[0046] at least one RNH₂ type primary amine or a R′RNH secondary amine,where R′ and R are advantageously selected from the group formed bycarbon-containing groups, alkyl, isoalkyl and naphthenyl groups, andaromatic groups which may or may not be substituted with other groupsand which may contain 1 to 16 carbon atoms;

[0047] at least one alkoxide of an element or a mixture of alkoxides,the element being selected from the group formed by silicon, aluminium,zirconium, titanium and vanadium, with general formula M(OR)_(n), whereM is the element described above, n is the valency of said element and Ris a group advantageously selected from the group formed by alkyl,isoalkyl and naphthenyl groups and aromatic groups which may or may notbe substituted. The different groups —OR may be identical or differentdepending on the nature of group R selected from the group definedabove.

[0048] It is left in contact, preferably with stirring, for example fora period in the range 5 minutes to 12 hours, preferably in the range 5minutes to 8 hours.

[0049] The bridged dioctahedral 2:1 phyllosilicate is then filtered anddried in air or in an inert gas, for example at a temperature in therange 40° C. to 150° C., for a period in the range 5 minutes to 24hours, preferably in the range 30 minutes to 12 hours.

[0050] This bridging process can simply and rapidly introduce SiO₂, Al₂O₃, TiO₂, ZrO₂, V₂O₅ struts or a mixture of these struts into the spacebetween the sheets of the dioctahedral 2:1 phyllosilicates,advantageously prepared in a fluoride medium.

[0051] In common with the base dioctahedral 2:1 phyllosilicate, thephyllosilicate of the invention has an X ray diffraction spectrum, whichenables the interplanar spacing d₀₀₁ to be calculated which issubstantially increased to at least 2.0×10⁻¹⁰ m. The specific surfacearea is also observed to have increased, generally between 200 and 1000m²/g, preferably between 250 and 700 m²/g. The d₀₆₀ lines of the X raydiffraction spectrum and the NMR lines of the ¹⁹F magic angle rotationspectrum are preserved.

[0052] The catalyst of the present invention thus also comprises atleast one amorphous or low crystallinity porous mineral matrix,generally an oxide. Non limiting examples are aluminas, silicas,silica-aluminas. Aluminates can also be used. Preferably, matricescontaining alumina in any of its forms which are known to the skilledperson, preferably gamma alumina, are used.

[0053] The catalyst also comprises a hydrogenating function. Thehydrogenating function per se, which has been defined above, i.e., atleast one metal selected from group VIB and/or group VIII, can beintroduced into the catalyst at various stages in the preparation and ina variety of manners.

[0054] The catalyst is also characterized in that it comprises apromoter element such as boron or silicon and optionally phosphorous. Itoptionally contains at least one group VIIA element, preferablyfluorine, and optionally at least one group VIIB element.

[0055] The catalyst of the present invention generally comprises, inweight % with respect to the total catalyst weight:

[0056] 0.1% to 60%, preferably 0.1% to 50%, more preferably 0.1% to 40%,of at least one metal selected from group VIB and group VIII (the %being expressed as the % of oxide);

[0057] 0.1% to 99%, preferably 1% to 99%, of at least one amorphous orlow crystallinity porous mineral matrix (generally an oxide);

[0058] 0.1% to 90%, preferably 0.1% to 80%, more preferably 0.1% to 70%,of at least one dioctahedral 2:1 phyllosilicate, preferably synthesisedin a fluoride medium, optionally bridged, said phyllosilicate whenbridged preferably having a large interplanar spacing of at least2.0×10⁻¹⁰ m;

[0059] said catalyst further comprising:

[0060] 0.1% to 20%, preferably 0.1% to 15%, more preferably 0.1% to 10%,of boron and/or silicon in its amorphous form, deposited on the supportand principally located on the support matrix (the % being expressed asthe % of oxide); and optionally:

[0061] 0 to 20%, preferably 0.1% to 15%, more preferably 0.1% to 10%, ofphosphorous (the % being expressed as the % of oxide);

[0062] 0 to 20%, preferably 0.1% to 15%, more preferably 0.1% to 10%, ofat least one element selected from group VIIA (halogens), preferablyfluorine;

[0063] 0 to 20%, preferably 0.1% to 15%, more preferably 0.1% to 10%, ofat least one element selected from group VIIB (the % being expressed asthe % of oxide).

[0064] The group VIB, group VIII and group VIIB metals in the catalystof the present invention can be completely or partially present in theform of the metal and/or oxide and/or sulphide.

[0065] The catalysts of the invention can be prepared using any suitablemethod. In general, a support is prepared comprising a porous matrixselected from the group formed by amorphous or low crystallinitymatrices, at least one clay selected from the group formed bydioctahedral 2:1 phyllosilicates and trioctahedral octahedral 2:1phyllosilicates, on which at least one metal selected from the groupformed by group VIB and group VIII metals is deposited, then the supportis impregnated with at least one solution selected from aqueoussolutions of boron and silicon. Preferably, the silicon and boron areintroduced into the catalyst already containing the support and at leastone metal selected from the group formed by group VIII and VIIBelements, and optionally group VIIB elements.

[0066] Preferably, a catalyst, for example a conventional hydrocrackingcatalyst of NiMo or NiMoP type containing a support comprising a mixtureof alumina and at least one dioctahedral 2:1 phyllosilicate, preferablysynthesised in a fluoride medium then bridged, said phyllosilicatehaving a large interplanar spacing, is impregnated with an aqueous boronsolution then with an aqueous silicon solution (or the reverse, thesilicon solution then the boron solution) or is impregnated with acommon aqueous solution containing boron and silicon.

[0067] The promoter element, in particular silicon introduced onto thesupport of the invention, is principally located on the matrix of thesupport and can be characterized by techniques such as a Castaingmicroprobe (distribution profile of the various elements), transmissionelectron microscopy coupled with X ray analysis of the catalystcomponents, or by producing a distribution map of the elements presentin the catalyst by electronic microprobe. These local analyses canfurnish the location of the various elements, in particular that of thepromoter element, especially that of the amorphous silica on the supportmatrix due to introduction of the silicon promoter. The location of thesilicon on the framework of the zeolite contained in the support is alsorevealed. Further, a quantitative estimate of the local silicon contentsor other promoter elements can be carried out.

[0068] In addition, ²⁹Si NMR with magic angle spinning is a techniquewhich can detect the presence of the amorphous silica introduced intothe catalyst using the procedure described in the present invention.

[0069] The invention also relates to a process for preparing saidcatalyst. More particularly, a process for preparing the catalyst of thepresent invention comprises the following steps:

[0070] a) drying and weighing a solid hereinafter termed the precursor,comprising at least the following compounds: a amorphous or lowcrystallinity porous matrix; at least one clay selected from the groupformed by dioctahedral 2:1 phyllosilicates and trioctahedral 2:1phyllosilicates, preferably dioctahedral 2:1 phyllosilicates, preferablysynthesised in a fluoride medium and optionally bridged, saidphyllosilicate having a large interplanar spacing; at least one elementfrom group VIB; and/or at least one element from group VIII; andoptionally phosphorous, the whole preferably being formed;

[0071] b) impregnating the precursor defined in step a) with an aqueoussolution containing boron and/or silicon, optionally phosphorous andoptionally at least one group VIIA element, preferably F;

[0072] c) leaving the moist solid in a moist atmosphere at a temperaturein the range 10° C. to 80° C.;

[0073] d) drying the moist solid obtained in step b) at a temperature inthe range 60° C. to 150° C.;

[0074] e) calcining the solid obtained from step c) at a temperature inthe range 150° C. to 800° C.

[0075] Step b) above can be carried out using conventional methods knownto the skilled person.

[0076] One preferred method of the invention consists of preparing anaqueous solution of at least one boron salt such as ammonium biborate orammonium pentaborate in an alkaline medium and in the presence ofhydrogen peroxide and introducing a silicone type silicon compound intothe solution and then dry impregnating, wherein the pore volume in theprecursor is filled with the solution containing B and Si. This methodproduces a better distribution of boron and silicon deposits than theconventional method using an alcoholic solution of boric acid or asolution of ethyl orthosilicate in alcohol.

[0077] The boron and silicon, and optional phosphorous, and optionallythe element selected from group VIIA, the halogen ions, preferablyfluorine, can be introduced into the catalyst at various stages of itspreparation and in a variety of manners.

[0078] The matrix is preferably impregnated using the “dry” impregnationmethod which is well known to the skilled person. Impregnation can becarried out in a single step using a solution containing all of theconstituent elements of the final catalyst.

[0079] The boron and silicon, and optional phosphorous, and optionallythe element selected from group VIIA, can be introduced into thecalcined precursor by one or more impregnation steps using an excess ofsolution.

[0080] Thus, for example, in the preferred case where the precursor is anickel-molybdenum type catalyst supported on a support formed of aluminaand at least one dioctahedral 2:1 phyllosilicate, preferably synthesisedin a fluoride medium (in the presence of hydrofluoric acid and/oranother source of fluoride anions), optionally bridged, saidphyllosilicate having a large interplanar spacing, it is possible toimpregnate this precursor with an aqueous solution of ammonium biborateand Rhodorsil E1P silicone from Rhone Poulenc, to dry at 80° C., forexample, then to impregnate with a solution of ammonium fluoride, to dryat 80° C., for example, and then to calcine, preferably carried out inair in a traversed bed, for example at 500° C. for 4 hours.

[0081] Other impregnation sequences can be carried out to obtain thecatalyst of the present invention.

[0082] Thus it is possible to impregnate with the solution containingsilicon, to dry, calcine then impregnate with the solution containingboron, to dry, then to carry out a final calcining step.

[0083] It is also possible to impregnate with the solution containingboron, to dry, calcine then impregnate with the solution containingsilicon, to dry, then to carry out a final calcining step.

[0084] When preparing a catalyst containing phosphorous, it is alsopossible to impregnate the precursor with a solution containingphosphorous, to dry, calcine then to impregnate with the solutioncontaining boron, to dry, calcine then impregnate with the solutioncontaining silicon, to dry, then to carry out a final calcining step.

[0085] When the metals are introduced in a plurality of steps forimpregnating the corresponding precursor salts, an intermediate catalystdrying step is generally carried out at a temperature which is generallyin the range 60° C. to 250° C.

[0086] The preferred phosphorous source is orthophosphoric acid H₃PO₄,but its salts and esters such as ammonium phosphates are also suitable.Phosphorous can, for example, be introduced in the form of a mixture ofphosphoric acid and a basic organic compound containing nitrogen, suchas ammonia, primary and secondary amines, cyclic amines, pyridine groupcompounds, quinolines, and pyrrole group compounds.

[0087] A variety of silicon sources can be used. Examples are ethylorthosilicate Si(OEt)₄, siloxanes, polysiloxanes, silicones, siliconeemulsions and halogenated silicates such as ammonium fluorosilicate(NH₄)₂SiF₆ or sodium fluorosilicate Na₂SiF₆. Silicomolybdic acid and itssalts, and silicotungstic acid and its salts can also advantageously beused. Silicon can be added, for example, by impregnating ethyl silicatein solution in a water/alcohol mixture. Silicon can be added, forexample, by impregnation using an emulsion of a silicone in water.

[0088] The boron source can be boric acid, preferably orthoboric acidH₃BO₃, ammonium biborate or pentaborate, boron oxide, or boric esters.Boron can, for example, be introduced in the form of a mixture of boricacid, hydrogen peroxide and a basic organic compound containingnitrogen, such as ammonia, primary and secondary amines, cyclic amines,pyridine group compounds, quinolines, and pyrrole group compounds. Boroncan, for example, be introduced using a solution of boric acid in awater/alcohol mixture.

[0089] Sources of group VIIA elements which can be used are well knownto the skilled person. As an example, fluoride anions can be introducedin the form of hydrofluoric acid or its salts. Such salts arc formedwith alkali metals, ammonium or an organic compound. In the latter case,the salt is advantageously formed in the reaction mixture by reactingthe organic compound with hydrofluoric acid. It is also possible to usehydrolysable compounds which can liberate fluoride anions in water, suchas ammonium fluorosilicate (NH₄)₂SiF₆, silicon tetrafluoride SiF₄ orsodium fluorosilicate Na₂SiF₆. Fluorine can be introduced, for example,by impregnating with an aqueous hydrofluoride solution or ammoniumfluoride.

[0090] Sources of group VIB elements which can be used are well known tothe skilled person. Examples of molybdenum and tungsten sources areoxides and hydroxides, molybdic acids and tungstic acids and theirsalts, in particular ammonium salts such as ammonium molybdate, ammoniumheptamolybdate, ammonium tungstate, phosphomolybdic acid,phosphotungstic acid and their salts. Preferably, oxides and ammoniumsalts are used, such as ammonium molybdate, ammonium heptamolybdate andammonium tungstate.

[0091] The catalyst of the present invention can comprise at least onemetal selected from group VIB and/or VIII elements; the group VIII metalis preferably iron, cobalt or nickel.

[0092] Advantageously, the following combinations of metals are usednickel-molybdenum, cobalt-molybdenum, iron-molybdenum, iron-tungsten,nickel-tungsten, cobalt-tungsten. Preferred combinations are:nickel-molybdenum and nickel-tungsten. It is also possible to usecombinations of three metals, for example nickel-cobalt-molybdenum.

[0093] The sources of the group VIII elements which can be used are wellknown to the skilled person. Examples of sources of group VIII elementsare nitrates, sulphates, phosphates, halides, for example chlorides,bromides and fluorides, and carboxylates, for example acetates andcarbonates.

[0094] Sources of the group VIIB element which can be used are wellknown to the skilled person. Preferably, ammonium salts, nitrates andchlorides of group VIIB elements are used.

[0095] The catalyst of the present invention thus also comprises atleast one amorphous or low crystallinity porous mineral matrix,generally an oxide. This matrix is normally selected from the groupformed by aluminas, silicas and silica-aluminas or a mixture of at leasttwo of the oxides cited above. Aluminates can also be used. Preferably,matrices containing alumina in any of its forms which are known to theskilled person, preferably gamma alumina, are used.

[0096] Advantageously, mixtures of alumina and silica and mixtures ofalumina and silica-alumina can also be used.

[0097] Advantageously, mixtures of alumina and clay and mixtures ofsilica-alumina and clay can also be used.

[0098] Molybdenum impregnation can be facilitated by adding phosphoricacid to solutions of ammonium paramolybdate, which means thatphosphorous can also be introduced, to promote the catalytic activity.

[0099] The catalysts of the present invention are formed into grains ofdifferent shapes and dimensions. They are generally used in the form ofcylindrical or polylobed extrudates such as bilobes, trilobes, orpolylobes with a straight or twisted shape, but they can also beproduced and used in the form of compressed powder, tablets, rings,beads or wheels. The specific surface area is measured by nitrogenadsorption using the BET method (Brunauer, Emmett, Teller, J. Am. Chem.Soc., vol. 60, 309-316 (1938)) and is in the range 50 to 600 m²/g, thepore volume measured using a mercury porisimeter is in the range 0.2 to1.5 cm³/g and the pore size distribution may be unimodal, bimodal orpolymodal.

[0100] The invention also relates to processes for convertinghydrocarbon-containing feeds using the catalyst described above, and inparticular to hydrocracking processes.

[0101] The feeds used in the process are gasolines, kerosines, gas oils,vacuum gas oils, atmospheric residues, vacuum residues, atmosphericdistillates, vacuum distillates, heavy fuels, oils, waxes and paraffins,spent oil, deasphalted residues or crudes, feeds from thermal cracking(without hydrogen) or fluidised bed catalytic cracking processes (FCC),and their mixtures. They contain heteroatoms such as sulphur, oxygen andnitrogen and possibly metals.

[0102] In particular, the catalysts obtained are advantageously used forhydrocracking vacuum distillate type heavy hydrocarbons, deasphaltedresidues or hydrotreated residues or the like. The heavy cuts arepreferably constituted by at least 80% by volume of compounds with aboiling point of at least 350° C., preferably in the range 350° C. to580° C. They generally contain heteroatoms such as sulphur and nitrogen.The nitrogen content is usually in the range 1 to 5000 ppm by weight andthe sulphur content is in the range 0.01% to 5% by weight.

[0103] The hydrocracking conditions such as temperature, pressure,hydrogen recycle ratio, and hourly space velocity, can vary widelydepending on the nature of the feed, the quality of the desired productsand the facilities available to the refiner. The temperature isgenerally over 200° C. and usually in the range 250° C. to 480° C. Thepressure is over 0.1 MPa and usually over 1 MPa. The hydrogen recycleratio is a minimum of 50 and usually in the range 80 to 5000 normallitres of hydrogen per litre of feed. The hourly space velocity isgenerally in the range 0.1 to 20 volumes of feed per volume of catalystper hour.

[0104] The catalysts of the present invention preferably undergosulphurisation to transform at least part of the metallic species to thesulphide before bringing them into contact with the feed to be treated.This activation treatment by sulphurisation is well known to the skilledperson and can be carried out using any method already described in theliterature.

[0105] One conventional sulphurisation method which is well known to theskilled person consists of heating in the presence of hydrogen sulphideto a temperature in the range 150° C. to 800° C., preferably in therange 250° C. to 600° C., generally in a traversed bed reaction zone.

[0106] The catalyst of the present invention can advantageously be usedfor hydrocracking vacuum distillate type cuts containing largequantities of sulphur and nitrogen.

[0107] In a first implementation, or partial hydrocracking, also knownas mild hydrocracking, the degree of conversion is below 55%. Thecatalyst of the invention is thus used at a temperature which isgenerally 230° C. or more, preferably 300° C., generally at most 480°C., and usually in the range 350° C. to 450° C. The pressure isgenerally over 2 MPa and preferably 3 MPa. The quantity of hydrogen is aminimum of 100 normal litres of hydrogen per litre of feed and usuallyin the range 200 to 3000 normal litres of hydrogen per litre of feed.The hourly space velocity is generally in the range 0.1 h⁻¹ to 10 h⁻¹.Under these conditions, the catalysts of the present invention havebetter activities for conversion, hydrodesulphuration andhydrodenitrogenation than commercially available catalysts.

[0108] In a second implementation, the catalyst of the present inventioncan be used for partial hydrocracking, advantageously under moderatehydrogen pressure conditions, of cuts such as vacuum distillatescontaining high sulphur and nitrogen contents which have already beenhydrotreated. In this hydrocracking mode, the degree of conversion isbelow 55%. In this case, the petroleum cut is converted in two steps,the catalysts of the invention being used in the second step. Thecatalyst of the first step has a hydrotreatment function and comprises amatrix, preferably alumina-based, preferably containing no zeolite, andat least one metal with a hydrogenating function. Said matrix isselected from the group formed by alumina, silica, silica-alumina,magnesia, zirconia, titanium oxide and aluminates. The hydrotreatmentfunction is ensured by at least one metal or compound of a metal fromgroup VIII, such as nickel or cobalt. A combination of at least onemetal or compound of a metal from group VI of the periodic table (inparticular molybdenum or tungsten) and at least one metal or compound ofa metal from group VIII (in particular cobalt or nickel) can be used.When the catalyst comprises a metal from group VI and a metal from groupVIII, the total concentration of oxides of groups VI and VIII metals isin the range 5% to 40% by weight, preferably in the range 7% to 30% byweight, and the weight ratio, expressed as the metal oxide of the groupVI metal (or metals) to that of the group VIII metal (or metals), is inthe range 1.25 to 20, preferably in the range 2 to 10, Further, thiscatalyst can contain phosphorous. The phosphorous content in thefinished catalyst, expressed as the concentration of phosphorouspentoxide P₂O₅, is generally at most 15%, preferably in the range 0.1%to 15% by weight, and more preferably in the range 0.15% to 10% byweight. The catalyst can also contain boron in a ratio B/P=1.05 to 2(atomic), the sum of the B and P contents, expressed as the oxides,being between 5% and 15% by weight of the finished catalyst.

[0109] The first step is generally carried out at a temperature of 350°C. to 460° C., preferably 360° C. to 450° C.; the total pressure is atleast 2 MPa, preferably at least 3 MPa; and the hourly space velocity isin the range 0.1 h⁻¹ to 5 h⁻¹, preferably in the range 0.2 h⁻¹ to 2 h⁻¹,with a quantity of hydrogen at least 100 normal litres per normal litreof feed, preferably in the range 260 to 3000 normal litres per normallitre of feed.

[0110] In the second implementation, in the conversion step using thecatalyst of the invention (or second step), the temperatures aregenerally 230° C. or more and usually in the range 300° C. to 430° C.The pressure is generally at least 2 MPa, preferably at least 3 MPa; itis less than 12 MPa and preferably less than 10 MPa. The quantity ofhydrogen is a minimum of 100 litres per litre of feed and usually in therange 200 to 3000 litres of hydrogen per litre of feed. The hourly spacevelocity is generally in the range 0.15 h⁻¹ to 10 h⁻¹. Under theseconditions, the catalysts of the present invention have betteractivities for conversion, hydrodesulphuration, and hydrodenitrogenationand a better selectivity for middle distillates than commerciallyavailable catalysts. The service life of the catalysts is also improvedin the moderate pressure range.

[0111] In a third implementation, the catalyst of the present inventioncan be used for hydrocracking under high hydrogen pressure conditions ofat least 5 MPa, preferably at least 10 MPa, and advantageously at least12 MPa. The treated cuts are, for example, vacuum distillates containinghigh sulphur and nitrogen contents which have already been hydrotreated.In this hydrocracking mode, the degree of conversion is 55% or more. Inthis case, the petroleum cut conversion process is carried out in twosteps, the catalyst of the invention being used in the second step.

[0112] The catalyst used in the first step of the third implementationis identical to that used in the first step of the secondimplementation. It is used under the conditions described, the pressurebeing adjusted to that of the other implementation.

[0113] This first step is generally carried out at a temperature of350-460° C., preferably 360-450° C., a pressure of over 3 MPa, an hourlyspace velocity of 0.1-5 h⁻¹, preferably 0.2-2 h⁻¹, and with a quantityof hydrogen of at least 100 Nl/l of feed, preferably 260-3000 Nl/Nl offeed.

[0114] For the conversion step using the catalyst of the invention (orsecond step), the temperatures are generally 230° C. or more, usually inthe range 300° C. to 430° C. The pressure is in general more than 2 MPa,preferably more than 3 MPa. The quantity of hydrogen is a minimum of 100litres per litre of feed, usually in the range 200 to 3000 litres ofhydrogen per litre of feed. The hourly space velocity is generally inthe range 0.15 to 10 h⁻¹.

[0115] Under these conditions, the catalysts of the present inventionhave better activities for conversion and better selectivity for middledistillates than commercially available catalysts, even withconsiderably lower zeolite contents than those of commercially availablecatalysts.

[0116] The following examples illustrate the present invention withoutin any way limiting its scope.

[0117] A dioctahedral 2:1 phyllosilicate, PDP, was prepared, which was adioctahedral 2:1 phyllosilicate in the ammonium form.

[0118] The following were successively added to 36 g of distilled water:

[0119] 0.385 g of NH₄F salt (Prolabo), with moderate stirring;

[0120] 0.312 g of HF acid, 40% (Fluka);

[0121] 2.71 g of the hydrated oxyhydroxide AlOOH (Catapal B Vista), withvigorous stirring;

[0122] 2.50 g of powdered SiO₂ oxide (Aerosil 130 from Degussa), withmoderate stirring.

[0123] The composition of the hydrogel thus prepared, with respect toone mole of oxide SiO₂, was;

[0124] 1.0 SiO₂; 0.44Al₂O₃; 0.25 NaF; 0.15 HF; 48 H₂O giving, in molarterms: Si/Al = 1.136 NH₄ ⁺/Si = 0.25 F/Si = 0.40 HF/Si = 0.15 H₂O/Si =48

[0125] This composition did not take into account the water provided bythe aluminium source and the HF acid.

[0126] The hydrogel obtained was aged for 4 hours at ambient temperature(20° C.) with moderate stirring. The pH was close to 5.

[0127] Crystallisation was then carried out at 220° C. in a 120 ml steelautoclave lined with a Teflon coating, under autogenous pressure, for168 hours, without stirring. The autoclave was then cooled in air. ThepH at the end of the synthesis was about 5.5.

[0128] The product was recovered, filtered and washed with copiousquantities of distilled water. It was then dried at 40-50° C. for 24hours. After 24 hours, the product obtained, with 50% relative humidity,was characterised by its X ray diffraction spectrum, shown below (Table1). TABLE 1 d_(hkl) (10⁻¹⁰) I/I_(o) 10.87 73 5.32 12 4.46 100  2.58 302.56 43 2.2 46 2.1 77 2.0 77 1.69 11 1.49 22

[0129] The fluorine content of the phyllosilicate obtained was 2.9% byweight. For ¹⁹F NMR with magic angle spinning of the phyllosilicateprepared in this example, a signal was present at −133 ppm.

[0130] The prepared dioctahedral 2:1 phyllosilicate in its ammonium formwas termed PD. This latter then underwent a bridging step using theprocedure described below. 8 g of the prepared dioctahedral 2:1phyllosilicate PD was suspended in 80 ml of a hexadecyltrimethylammonium(CTMA-CI) solution with a concentration of 0.1 M. After 1 hour ofstirring at room temperature, it was filtered, washed with twice 200 mlof distilled water then dried at 60° C. for 8 hours. The PD samplepreviously treated with CTMA was suspended in a mixture composed of 4.48g of octylamine (C₈H₁₇NH₂) and 60.32 g of ethyl tetraorthosilicate(Si(OEt)₄), and 2.96 g of aluminium isopropoxide After 30 minutesstirring, it was filtered then dried at 60° C. for 8 hours. The samplewas calcined at 530° C. for 3 hours in air then for 2 hours in pureoxygen. The d₀₀₁ of the sample after calcining was 31.2 Å and itsspecific surface area was 375 m²/g. The prepared dioctahedral 2:1phyllosilicate was termed PDP.

[0131] Large quantities of a hydrocracking catalyst containingdioctahedral 2:1 phyllosilicate PD were produced so as to enabledifferent catalysts based on the same support to be prepared. To thisend, 19.3% by weight of dioctahedral 2:1 phyllosilicate PD was mixedwith 80.7% by weight of a matrix composed of ultrafine tabular boehmiteor alumina gel sold by Condéa Chemie GmbH under the trade name SB3. Thispowder mixture was then mixed with an aqueous solution containing 66%nitric acid (7% by weight of acid per gram of dry gel) then milled for15 minutes. After milling, the paste obtained was passed through a diewith cylindrical orifices with a diameter of 1.4 mm. The extrudates weredried overnight at 120° C. then calcined at 550° C. for 2 hours in air.

[0132] Large quantities of a hydrocracking catalyst containing bridgeddioctahedral 2:1 phyllosilicate PDP were produced so as to enabledifferent catalysts based on the same support to be prepared. To thisend, 20.5% by weight of bridged dioctahedral 2:1 phyllosilicate PDP wasmixed with 79.5% by weight of a matrix composed of ultrafine tabularboehmite or alumina gel sold by Condéa Chemie GmbH under the trade nameSB3. This powder mixture was then mixed with an aqueous solutioncontaining 66% nitric acid (7% by weight of acid per gram of dry gel)then milled for 15 minutes. After milling, the paste obtained was passedthrough a die with cylindrical orifices with a diameter of 1.4 mm. Theextrudates were dried overnight at 120° C. then calcined at 550° C. for2 hours in air.

EXAMPLE 1 Preparation of catalysts containing a bridged dioctahedral 2:1phyllosillcate

[0133] Extrudates of the support containing bridged dioctahedral 2:1phyllosilicate PDP prepared as described above were dry impregnated withan aqueous solution of a mixture of ammonium heptamolybdate and nickelnitrate, dried overnight at 120° C. in air and finally calcined at 550°C. in air. The oxide weight contents of the catalyst obtained are shownin Table 2. The final catalyst CZ14 contained 17.4% by weight of bridgeddioctahedral 2:1 phyllosilicate PDP.

[0134] Extrudates of the support containing bridged dioctahedral 2:1phyllosilicate PDP were dry impregnated with an aqueous solution of amixture of ammonium heptamolybdate, nickel nitrate and orthophosphoricacid, dried overnight at 120° C. in air and finally calcined at 550° C.in air. Catalyst CZ14P was obtained.

[0135] We impregnated a sample of catalyst CZ14P described above with anaqueous solution comprising ammonium biborate. After ageing at roomtemperature in an atmosphere saturated with water, the impregnatedextrudates were dried overnight at 120° C. then calcined at 550° C. for2 hours in dry air. Catalyst CZ14PB was obtained:NiMo/alumina-beidellite doped with boron.

[0136] A catalyst CZ14PSi was obtained using the same procedure as thatfor CZ14PB above, replacing the boron precursor in the impregnationsolution with a Rhodorsil EP1 (Rhone Poulenc) silicone emulsion.

[0137] Finally, a catalyst CZ14PBSi was obtained by impregnatingcatalyst CZ14P an aqueous solution comprising ammonium biborate and aRhodorsil EP1 silicone emulsion (Rhone Poulenc). The other steps of theprocedure were the same as those indicated above. Fluorine was thenadded to this catalyst by impregnating with a solution of dilutehydrofluoric acid to deposit about 1% by weight of fluorine. Afterdrying overnight at 120° C. and calcining at 550° C. for 2 hours in dryair, catalyst CZ14PBSiF was obtained. The final oxide contents ofcatalysts CZA are shown in Table 2. TABLE 2 Characteristics of CZ14catalysts CZ14 CZ14 CZ14 CZ14 Catalyst CZ14 PB PSi PBSi PBSiF MoO₃ 12.311.6 11.6 11.4 11.2 (wt %) NiO (wt %) 2.8 2.7 2.7 2.6 2.6 P₂O₅ 0 4.7 4.74.6 4.6 (wt %) B₂O₃ 0 1.9 0 1.8 1.8 (wt %) SiO₂ 11.6 10.8 12.6 12.3 12.1(wt %) F (wt %) 0 0 0 0 1.5 Complement 73.3 68.3 68.4 67.3 66.2 to 100%,mainly composed of Al₂O₃ (wt %)

[0138] Catalyst CZ14P was then impregnated with an aqueous solutioncomprising manganese nitrate. After ageing at room temperature in anatmosphere saturated with water, the impregnated extrudates were driedovernight at 120° C. then calcined at 550° C. for 2 hours in dry air.Catalyst CZ14PMn was obtained. This catalyst was then impregnated withan aqueous solution comprising ammonium biborate and Rhodorsil EP1silicone emulsion (Rhone-Poulenc). The impregnated extrudates were driedovernight at 120° C. then calcined at 550° C. for 2 hours in dry air toproduce catalyst CZ14PMnBSi. Fluorine was then added to this catalyst byimpregnating with a solution of dilute hydrofluoric acid to depositabout 1% by weight of fluorine. After drying overnight at 120° C. andcalcining at 550° C. for 2 hours in dry air, catalyst CZ14PMnBSiF wasobtained. The oxide contents of these catalysts are shown in Table 3.TABLE 3 Characteristics of CZ14 catalysts containing manganese CZ14 CZ14Catalyst PMnBSi PMnBSiF MoO₃ (wt %) 11.1 10.9 NiO (wt %) 2.5 2.5 MnO₂(wt %) 1.9 1.9 P₂O₅ (wt %) 4.7 4.6 B₂O₃ (wt %) 1.7 1.8 SiO₂ (wt %) 12.111.9 F (wt %) 0 1.6 Complement to 100%, 66.0 64.8 mainly composed ofAl₂O₃ (wt %)

[0139] Electronic microprobe analysis of catalysts CZ14PSi, CZ14PBSi,CZ14PBSiF (Table 2) and catalysts CZ14PMnBSi, CZ14PMnBSiF (Table 3)showed that the silicon added to the catalyst of the invention wasprincipally located on the matrix and was in the form of amorphoussilica.

EXAMPLE 2 Preparation of catalysts containing a non-bridged dioctahedral2:1 phyllosilicate

[0140] Extrudates of the support containing non-bridged dioctahedral 2:1phyllosilicate PD prepared as described above were dry impregnated withan aqueous solution of a mixture of ammonium heptamolybdate, nickelnitrate and orthophosphoric acid, dried overnight at 120° C. in air andfinally calcined at 550° C. in air. Catalyst CZ19P was obtained.

[0141] Catalyst CZ19P was then impregnated with an aqueous solutioncomprising ammonium biborate and a Rhodorsil EP1 silicone emulsion(Rhone Poulenc). The impregnated extrudates were then dried overnight at120° C. and calcined at 550° C. for 2 hours in dry air; catalystCZ19PBSi was obtained. TABLE 4 Characteristics of CZ19 catalysts CZ19CZ19 Catalyst P PBSi MoO₃ (wt %) 12.0 11.6 NiO (wt %) 2.8 2.7 P₂O₅ (wt%) 4.6 4.4 B₂O₃ (wt %) 0 1.9 SiO₂ (wt %) 7.3 8.7 Complement to 100%,73.3 70.7 mainly composed of Al₂O₃ (wt %)

[0142] Electronic microprobe analysis of catalyst CZ19PBSi (Table 4)showed that the silicon added to the catalyst of the invention wasprincipally located on the matrix and was in the form of amorphoussilica.

EXAMPLE 3 Comparison of catalysts for partial conversion hydrocrackingof a vacuum gas oil

[0143] The catalysts prepared in the above Examples were employed undermoderate pressure hydrocracking conditions using a petroleum feed withthe following principal characteristics: Density (20/4) 0.921 Sulphur(weight %) 2.46 Nitrogen (ppm by weight) 1130 Simulated distillationInitial point 365° C. 10% point 430° C. 50% point 472° C. 90% point 504°C. End point 539° C. Pour point +39° C.

[0144] The catalytic test unit comprised two fixed bed reactors inupflow mode. The catalyst for the first hydrotreatment step of theprocess, HTH548 from Procatalyse, comprising a group VI element and agroup VIII element deposited on alumina, was introduced into the firstreactor, through which the feed passed first. A hydrocracking catalystas described above was introduced into the second reactor, through whichthe feed passed last. 40 ml of catalyst was introduced into each of thereactors. The two reactors operated at the same temperature and the samepressure. The operating conditions of the test unit were as follows:Total pressure 5 MPa Hydrotreatment catalyst 40 cm³ Hydrocrackingcatalyst 40 cm³ Temperature 400° C. Hydrogen flow rate 20 1/h Feed flowrate 40 cm³/h

[0145] The two catalysts underwent in-situ sulphurisation before thereaction. It should be noted that any in-situ or ex-situ sulphunsationmethod is suitable. Once sulphurisation had been carried out, the feeddescribed above could be transformed.

[0146] The catalytic performances are expressed as the gross conversionat 400° C. (GC), the gross selectivity for middle distillates (GS) andthe hydrodesulphuration (HDS) and hydrodenitrogenation (HDN)conversions. These catalytic performances were measured for the catalystafter a stabilisation period, generally of at least 48 hours, hadpassed.

[0147] The gross conversion GC is taken to be:

[0148] GC=weight % of 380° C. of effluent.

[0149] 380° C. represents the fraction boiling below 380° C.

[0150] The gross selectivity GS for middle distillates is taken to be;

[0151] GS=100* weight of (150° C.-380° C.) fraction/weight of 380° C.fraction of effluent.

[0152] The hydrodesulphuration conversion HDS is taken to be:

[0153]HDS=(S_(initial)−S_(effluent))/S_(initial)*100=(24600−S_(effluent))/24600 *100

[0154] The hydrodenitrogenation conversion HDN is taken to be:

[0155] HDN=(N_(initial)−N_(effluent))/N_(initial)*100=(1130−N_(effluent))/1130 * 100

[0156] Table 5 below shows the gross conversion GC at 400° C., the grossselectivity GS, the hydrodesulphuration conversion HDS and thehydrodenitrogenation conversion HDN for the four catalysts. TABLE 5Catalytic activities of catalysts for partial hydrocracking at 400° C.GC GS HDS HDN (wt %) (%) (%) (%) CZ14 NiMo/PDP 42.9 81.0 98.1 92.5CZ14PB NiMoPB/PDP 43.5 81.8 98.57 94.2 CZ14PSi NiMoPSi/PDP 43.8 81.998.56 94.8 CZ14PBSi NiMoPBSi/PDP 44.7 81.1 98.73 96.6

[0157] The results of Table 5 show that combining the two dopants Band/or Si improves the performances of the catalyst containing a bridgeddioctahedral 2:1 phyllosilicate for conversion. The gross selectivityfor middle distillates reduced because of the increase in the degree ofconversion, as is well known. The catalysts of the invention containingboron and/or silicon are thus or particular interest for partialhydrocricking of a vacuum distillate type feed containing nitrogen at amoderate hydrogen pressure.

EXAMPLE 4 High conversion hydrocracking tests carried out on a vacuumgas oil

[0158] The catalysts prepared as described above were used under highconversion (60-100%) hydrocracking conditions on a vacuum distillatetype feed with a high sulphur and nitrogen content with the followingprincipal characteristics: Density at 15° C. 0.912 Sulphur 2.22% byweight Total Nitrogen 598 ppm by weight Simulated distillation Initialpoint 345° C. 10% point 375° C. 50% point 402° C. 90% point 428° C. Endpoint 467° C.

[0159] The catalytic test unit comprised a fixed bed reactor operatingin upflow mode. The hydrocracking test was carried out under thefollowing operating conditions: Total pressure 20 MPa Catalyst volume 40cm³ Temperature 370-420° C. Hydrogen flow rate 24 1/h Feed flow rate 20cm³/h

[0160] Each catalyst was sulphurised before the test at 350° C. and at atotal pressure of 20 MPa using the feed to which 2% by weight ofdimethyldisulphide (DMDS) had been added.

[0161] Under these conditions, the catalytic performances forhydrodesulphuration (HDS) and hydrodenitrogenation (HDN) were such thatthe sulphur and nitrogen contents in the effluent were below thedetection limit of standard analysis techniques. This observation isnormal taking into account the high pressure of the hydrogen used. Thegross conversion (GC) is of principal interest. These catalyticperformances were measured using the catalyst after a stabilisationperiod, generally of at least 48 hours, had passed.

[0162] The gross conversion GC is taken to be:

[0163] GC=weight % of 380° C. of effluent.

[0164] Table 6 below shows the gross conversion GC at 410° C. for thecatalysts tested under these conditions and the gross selectivity formiddle distillates (150-380° C.). TABLE 6 Catalytic activities ofcatalysts for high conversion hydrocracking GC GS (%) CZ14 NiMo/PDP 76.170.3 CZ14PB NiMoPB/PDP 78.3 69.2 CZ14PSi NiMoPSi/PDP 80.1 68.3 CZ14PBSiNiMoPBSi/PDP 84.2 66.8 CZ14PBSiF NiMoPBSiF/PDP 85.1 66.2 CZ19P NiMoP/PD75.2 71.1 CZ19PBSi NiMoPBSi/PD 81.2 68.0 CZ14PMnBSi NiMoPMnBSi/PDP 84.966.5 CZ14PMnBSiF NiMoPMnBSiF/PDP 86.0 65.7

[0165] Adding boron and/or silicon to the catalyst containing a bridgeddioctahedral 2:1 phyllosilicate improved the conversion activity,meaning an increase in the degree of conversion at 410° C. The grossselectivity for middle distillates reduced because of the increase inthe degree of conversion, as is well known.

[0166] Catalyst CZ14PBSi containing boron and silicon was thus ofparticular interest for use in processes for hydrocracking vacuumdistillate type feeds with a high sulphur and nitrogen content,generally termed hydrocracking using an amorphous catalyst at a highhydrogen pressure.

[0167] Similarly, adding boron and silicon to catalyst CZ19P containingnon bridged dioctahedral 2:1 phyllosilicate improved the conversionactivity, which resulted in an increase in the degree of conversion at410° C. The gross selectivity for middle distillates reduced because ofthe increase in the degree of conversion, as is well known.

[0168] Further, if manganese and/or fluorine was added, an improvementin the degree of conversion and thus in the converting activity was alsoobserved.

1. A catalyst, characterized in that it comprises at least one metalselected from the group formed by group VIB and group VIII and at leastone support containing at least one porous matrix selected from thegroup formed by amorphous or low crystallinity matrices and at least onebridged clay selected from the group formed by dioctahedral 2:1phyllosilicates and trioctahedral 2:1 phyllosilicates, the supportcontaining at least one promoter metal selected from the group formed byboron and silicon.
 2. A catalyst according to claim 1, characterized inthat it contains at least one bridged dioctahedral 2:1 phyllosilicatewith an interplanar spacing of at least 2.0×10⁻⁹ m and containing strutsbased on at least one of the compounds selected from the group formed bySiO₂, Al₂O₃, ZrO₂ and V₂O₅.
 3. A catalyst according to any one of thepreceding claims, characterized in that it contains phosphorous.
 4. Acatalyst according to any one of the preceding claims, characterized inthat it contains at least one element selected from the group formed bygroup VIIA, the halogens, and group VIIB.
 5. A catalyst according to anyone of claims 1 to 4, characterized in that the promoter element isprincipally deposited on the matrix.
 6. A catalyst according to any oneof claims 1 to 5, characterized in that the clay is a dioctahedral 2:1phyllosilicate prepared in a fluoride medium.
 7. A catalyst according toany one of claims 1 to 6, in which the elements selected from the groupformed by group VIB and group VIII are nickel-molybdenum,nickel-tungsten, cobalt-molybdenum, cobalt-tungsten ornickel-cobalt-molybdenum combinations.
 8. A catalyst according to anyone of claims 1 to 7, characterized in that it contains 0.1% to 60% ofat least one metal selected from group VIB and group VIII (as a % ofoxide); 0.1% to 99% of at least one porous mineral matrix selected fromthe group formed by amorphous or low crystallinity matrices; 0.1% to 90%of at least one dioctahedral 2:1 phyllosilicate; and between 0.1% and20% (as a % of oxide) of at least one promoter metal selected from thegroup formed by boron and silicon.
 9. A catalyst according to any one ofclaims 1 to 8, characterized in that it contains phosphorous present ina percentage, expressed as the percentage of oxides, in the range 0 to20%.
 10. A catalyst according to any one of claims 1 to 9, characterizedin that it contains at least one element selected from the group formedby group VIIA, the halogens, and group VIIB, the group VIIA elementbeing present in an amount in the range 0 to 20% and the group VIIBmetal being present in a percentage, expressed as the percentage ofoxide, in the range 0 to 20%.
 11. A process for preparing the catalystaccording to any one of claims 1 to
 10. 12. A process according to claim12, characterized in that a support is prepared which comprises a porousmatrix selected from the group formed by amorphous or low crystallinitymatrices, at least one clay selected from the group formed bydioctahedral 2:1 phyllosilicates and trioctahedral 2,1 phyllosilicates,on which at least one metal selected from the group formed by group VIBand group VIII is deposited, then the support is impregnated with atleast one solution selected from aqueous solutions of boron and silicon.13. A process according to claim 12, characterized in that the supportis impregnated with at least one aqueous phosphorous solution.
 14. Aprocess according to claim 12 or claim 13, characterized in that thesupport contains a group VIB element.
 15. A process according to any oneof claims 12 to 14, characterized in that the support is impregnatedwith at least one solution of group VIIA ions.
 16. Use of a catalystaccording to any one of claims 1 to 10 or obtained according to any oneof claims 11 to 15, for hydrocarbon conversion.
 17. Use of a catalystaccording to claim 16, for hydrocracking.